(often capitalized) Of or relating to the New Age movement. / Of or relating to New Age music.

(archaeology, paleontology) A broad prehistoric period during which humans widely used stone for toolmaking. / (figuratively, informal) Any extremely primitive or undeveloped era.

(archaeology) A period in a civilization's development when the most advanced metalworking has developed the techniques of smelting copper from natural outcroppings and alloys it to cast bronze.

Belonging in the Stone Age.

The age in which nuclear energy and nuclear weapons were developed.

the time of the Industrial Revolution

the period of life between youth and old age; midlife

(historical) A historical period of great accomplishment in a field or a society, usually following, and not quite as favorable as, a golden age, and not unfavorable as an iron age.

(idiomatic) A period of happiness, peace, prosperity, and/or great progress. / (mythology) The Golden Age.

The era, starting in the mid-1940s, during which nuclear energy was developed, and in which it was thought that all energy would be provided by such sources.